The present invention relates to a pulse generator, in particular, relates to a voltage controlled pulse generator in a horizontal and/or vertical deflection circuit of a television set.
One prior pulse generator used in deflection circuits is a multivibrator having two capacitors. However, in order to manufacture the pulse generator in an IC chip, the number of external components outsides the IC chip should be as few as possible. Since the multivibrator type pulse generator must have two external capacitors, this prior pulse generator is not suitable for an IC chip.
To overcome the above problem, an IC type pulse generator, which uses only a single external capacitor has been produced. Some examples of this type of pulse generator are, TAA790 manufactured by ITT Semiconductors Company, XC1391P by Motorala Company and .mu.PC570C by Nippon Electric Company. These pulse generators have an integrator circuit with a resistor and a capacitor, which is charged and discharged alternately. The voltage across said capacitor is compared with a reference voltage, and according to the result of the comparison, the capacitor is charged or discharged. Said reference voltage has two levels relating to the status of the circuit. However, the prior pulse generators including TAA790, XC1391P and .mu.PC570C have the disadvantage that the pulse frequency is changed due to changes in the circumferential temperature and compensation of such frequency change is rather difficult.